Control strategies of VSC-HVDC transmission system for wind power integration to meet GB grid code requirements

This paper presents control strategies for a DC transmission system connecting onshore/offshore wind farms to the power network. These control strategies aim to allow the VSC-HVDC transmission system to meet the Great Britain (GB) Grid Code regarding frequency support, voltage/or reactive power support and Fault Ride-Through capability. This paper utilizes the kinetic energy of the wind turbine generators and the energy stored in the DC link capacitors of wind farm side converter to provide short to medium term frequency support to the AC network. The grid side converter is used to provide reactive power/or voltage support to the AC network during AC faults which cause voltage dips as low as 0.15pu (retained voltage). A reduced network model of Scotland and England has been implemented in Matlab/Simulink to assess control performance. Key results are presented and discussed